The invention relates to a winding apparatus with a guiding means, by means of which a drawing means can be guidedly taken up on a cylindrical drum surface of a reel rotating about an axis relative to the guiding means.
Such a winding apparatus is generally known for taking up a carrier cable of a mains-power operated suspended luminaire, wherein the carrier cable is guided within the spirally wound mains cable for supplying the suspended luminaire with electrical power.
Such winding apparatuses are generally, for appearance reasons, concealed in the ceiling fixture of the suspended luminaire, under a suspended ceiling, for example. In the conventional suspended luminaire equipped with ceiling fastener hooks for mounting, the winding apparatus is usually integrated in a covering concealing said hooks and the power feed, whereby said covering is necessarily naturally larger than in comparable lighting fixtures not having level adjusting means.
The known winding apparatus comprises essentially a horizontally disposed reel for taking up the carrier cable into a plastic housing that is closed, save for an entry aperture disposed in the bottom part thereof for admitting the carrier cable. The carrier rope is wound or unwound in said housing by rotating the reel about its axis, whereby a torsion spring disposed on the housing and the reel substantially maintains the balance of the weight force of the luminaire member. In this fashion the luminaire member can be adjusted to a desired height without great expenditure of force within the predefined range of the length of the carrier rope.
The known winding apparatuses are hardly appropriate for implementation in the field of low-voltage lighting technology because of their considerable intrinsic dimensions.
The object of the present invention is to provide a winding apparatus which, by virtue of its dimensions, is suitable as a height adjustment of a low-voltage suspended luminaire and can be connected with same in an optically advantageous fashion.
On the basis of the winding apparatus described at the beginning, said object is achieved in that the axis of the reel is oriented in the direction in which the drawing material runs upon entry into the winding apparatus. In this fashion, the winding apparatus can be configured particularly narrowly and especially optically appropriately in the case of a suspended luminaire.
In a preferred embodiment of the invention the reel is formed as to be displaceable in the direction of its axis relative to the guiding direction. The windings of the drawing material can be taken up axially offset on the reel.
A necessary coupling of the rotation and translatory movement of the reel relative to the guiding direction can be realized without additional mechanical components by interlocking threads in a contact surface of the two components. If the chosen pitch of the thread is (at least slightly) greater than the diameter of the drawing material then the successive coils of the drawing material are taken up in a particularly simple fashion alongside each other on the reel.
The number of components of the winding apparatus according to the invention can be kept to a minimum if the thread on the drum surface of the reel and on an inner cylinder surface are applied to a guiding means encircling the reel. If in this instance (as described above) the leadxe2x80x94or pitchxe2x80x94of the thread is greater than the diameter of the drawing material, then the latter is specifically taken up in the thread troughs. If two separate drawing materials are taken up on the same reel at the same timexe2x80x94for example in the case of a low-voltage halogen luminaire suspended on two linesxe2x80x94said thread is particularly advantageously executed having a double thread.
In an alternative embodiment the guiding means comprises a spike with a thread on the external side, said spike engaging with an inner thread of the reel. The drawing material is then preferably taken up on a non-profiled drum surface. In order to keep manufacturing costs low, the spike can be manufactured out of a thermoplastic synthetic material using an injection molding process and integrated with the formed thread in one single work step. High-quality material that is more costly to workxe2x80x94metal (aluminum for example) or colored glassxe2x80x94can be used for those components of the guiding means that comprise visible surfaces.
Preferably, the winding apparatusxe2x80x94especially when used for adjusting the height of a suspended luminairexe2x80x94can be equipped with a driver device which eliminates manual intervention in the winding apparatus for winding or unwinding the drawing material. As in the case of the winding apparatuses known from the prior art, a torsion spring can be used as the driver device, which maintains the balance of a drawing force in the drawing material. The winding and unwinding of the drawing material is then set into motion by a slight change in the tractive forcexe2x80x94by slight lifting of the body of the lamp body of the suspended luminaire, for example.
A further embodiment comprisesxe2x80x94alternatively or in addition to the torsion springxe2x80x94a motor which is, for example, controlled by a logical circuit integrated in the winding apparatus and an optical sensor enables contact-less winding and unwinding of the drawing materialxe2x80x94for example for adjusting the height of a suspended luminaire.
In a preferred embodiment of the winding apparatus according to the invention, the drawing material is first led through the reel and only then through the guiding means on the drum surface of the reel. In particular in the case of use as a height adjustment for a suspended luminaire there is the advantage that only the upper end of the winding apparatusxe2x80x94in this case, the reelxe2x80x94rotates relative to the drawing material. This rotational movement is thus not transferred to the lamp body below the winding apparatusxe2x80x94in this case, the guiding means.
The winding apparatus according to the invention can be used particularly for adjusting the height of a suspended luminaire. Because of the fact that the longitudinal axis of the reel lies in the direction of the drawing material the winding apparatus is particularly optically advantageous when integrated into the typical filigree construction of a low-voltage luminaire.
The impression of the simplicity of the construction is especially supported, when the drawing material carrying the luminaire is an electrical cable providing the electrical supply to the luminaire, especially when both lines are integrated in itxe2x80x94in this instance the use of a coaxial cable is preferred. If a coaxial cable is used that is not insulated to the outside, then the luminaire can be particularly easily combined with a contact dimmer as has been disclosed in DE 196 28 891.
A variety of possible designs for such a suspended luminaire using the winding apparatus according to the invention result especially if it is incorporated with the luminaire member in one structural unit.